In vehicular exhaust treatment systems, high temperature exhaust gas poses problems with safety, durability and increased exhaust flow noise. In some vehicle applications, exhaust gas temperatures can become high at idle conditions, resulting in a need for exhaust cooling arrangements. Commonly used sound absorbing materials used in exhaust resonators may fail at increased exhaust temperatures resulting in undesirable exhaust sound levels. Furthermore, high temperature exhaust gas leads to decreased gas density, thus increasing exhaust gas velocity which creates high frequency flow noise. Exhaust treatment devices, such as resonators, therefore need to take those problems into account in their design.